The objective of this project is to audit the deHaen Drugs-in-Use drug information system for accuracy and completeness of abstraction. A random selection process was designed to select deHaen abstracts for auditing. The corresponding original reference was then obtained and completely reviewed to determine the accuracy and completeness of the abstraction. This study has been completed with the audit of 100 abstracts. The results showed that 47 cards contained at least one error, with a total of 66 errors being detected. The major category of error involved was inaccurate data. The subscriber of this drug information source is urged to use the deHaen system only as a secondary reference source. All data obtained should be confirmed with the original reference.